False and misleading information

Oh look! again! Remember kids, it’s not just compilers that you should keep around, but libc/binutils, and all libraries you’re ever going to use.

Today it’s avr-libc, and this gem:

In file included from ../../common/FreqCounter.h:17:0,
                 from ../../common/FreqCounter.c:35:
/usr/avr/include/util/delay.h: In function '__vector_21':
/usr/avr/include/util/delay.h:246:2: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
  ^

Apparently it was always actually a requirement in the notes, but everyone did it anyway. Now, you need to write a wrapper function like this sort of shit:

void do_what_I_say_delay_us(int us) {
     while (us-- > 0) {
         _delay_us(1);
     }
}

Hooray, isn’t that better for everyone! See http://nongnu.org/avr-libc/user-manual/group__util__delay.html for more information, if you can read carefully enough :)